Cheap electricity (just cents / kWh) from CHP appliance

[George Davidson]

I would like to open a discussion on sources of cheap electricity for our EVs.

Currently, for overnight charging, we pay over CAD 0.20 / kWh. Charging at L3 fast chargers gets around CAD 0.50 / kWh at Petro Canada, FLO. And with Kona BMS throttling charging to some 25 kW at low temperatures it can get to CAD 0.80 / kWh (the worst case).

So far the only real cheap one I came across seems to be CHP - just a few cents per kWh.

CHP examples:

https://www.axiom-energy.com/

https://enginuitypowersystems.com/products/home-m-chp/

http://www.gonextgrid.com/products/nextgrid-chp-models/

https://www.rmbenergie.com/en/

https://www.vitovalorinstaller.com/

http://www.greengiantservices.co.uk/vitovalor.html

https://fuelcellsworks.com/news/germany-number-of-fuel-cells-for-household-energy-continues-to-rise/

Taking into account our natural gas furnace is running 7-8 months a year it would make sense for us to replace it with CHP and charge our Kona EV pretty much for "free" overnight.

 

[Shawn Schinkel]

That seems like a pretty awesome idea. I’ve been toying with the idea of a Generac standby generator for years, but it’s hard to drop 4-5k on something that ideally never gets used. This would solve the generator problem, get rid of the rental hot water tank, and drop the electricity bill. Seems like a good idea! Do you know if this is available in Ontario Canada?


Sent from my iPhone using Tapatalk

 

[Genevamech]

Keep in mind that CHP equipment isn't magic; that energy is still coming from somewhere. CHP efficiency is usually listed as "total" - electricity + heat. This is a bit of a shell game, because a modern gas-fired hot water boiler by itself is >95% efficient and hides the rather awful efficiency of the combustion engine.

Using the NextGrid GT1500 from your third link as an example, plus Google telling me that natural gas costs about CAD 0.039 per kWh, I'm coming up with about CAD 0.41 per kWh electricity. Nearly twice as much as what you're paying now. I can show my work if you want... you're also getting about 85 gallons of hot water per hour, so unless you're using that much hot water (obviously home heating is the only practical way to do so) it's all going to waste.

Of course having a CHP plant is better than a generator alone, and gas service tends to be more reliable than electricity service so that's also something to consider. That's not related to costs, though.

Probably the best cost per kWh will still be solar PV, given that the operating costs is essentially zero.

 

[Jim Matthews]

I looked into a CHP replacement for my ancient Oil fired boiler.

It was cheaper (and uses less Natural gas) to install a Veissman Vitodens condensing boiler for heating and an LG battery backup if the power goes out. (Even at .20 USD per kWh).

If you're keen to offset charging costs, PV arrays offer the best ROI, even North of the 49th.

 

[cregox]

took me a while to discover that CHP means combined heat and power... and even longer to understand it's only about gas, in practice. i won't bother to look up PV (which is even worse to stfw for).

if you want a real alternative, i don't think we're quite there yet, but they do exist at least in theory (and half practice):

https://h2nrgy.com/videos/

but as per this post...

Keep in mind that CHP equipment isn't magic; that energy is still coming from somewhere. CHP efficiency is usually listed as "total" - electricity + heat. This is a bit of a shell game, because a modern gas-fired hot water boiler by itself is >95% efficient and hides the rather awful efficiency of the combustion engine.

Using the NextGrid GT1500 from your third link as an example, plus Google telling me that natural gas costs about CAD 0.039 per kWh, I'm coming up with about CAD 0.41 per kWh electricity. Nearly twice as much as what you're paying now. I can show my work if you want... you're also getting about 85 gallons of hot water per hour, so unless you're using that much hot water (obviously home heating is the only practical way to do so) it's all going to waste.

Of course having a CHP plant is better than a generator alone, and gas service tends to be more reliable than electricity service so that's also something to consider. That's not related to costs, though.

Probably the best cost per kWh will still be solar PV, given that the operating costs is essentially zero.

going cheap will require nothing less than solar power indeed. funny enough, it is less subsidized than all other forms of energy (including wind and water), and it's still far cheaper and cleaner. and yet, too few people pay attention to it.

if you're serious about your savings, and got the resources, please, do look it up and keep digging on.

there are so much and many better ways...

 

[Genevamech]

i won't bother to look up PV

Photovoltaic, i.e. "solar panels" - the kind that produce electricity. There is also solar thermal panels which use sunlight to heat up water (or sometimes oil) so sometimes just saying "solar power" isn't specific enough.

 

[apu]

Photovoltaic, i.e. "solar panels" - the kind that produce electricity. There is also solar thermal panels which use sunlight to heat up water (or sometimes oil) so sometimes just saying "solar power" isn't specific enough.

Unless your delivered electricity rates are significantly above 12 cents/kW, you have a massive scaled system or have very favorable grid tie rates its hard to make solar electricity cheaper.

We have a non grid tied 3kW solar array that I installed myself(saved at least 10K in labor) and the best I can do is be currently be cost neutral(~ 11.5cents/kW) and maybe future rate proofed as an electricity producer. Its currently 12.35 cents/kW taxed and delivered for the same amount of power from my provincial crown corporation Hydro electric provider. My costs are based on amortization of replacement battery banks and repair /replacement of electronics such as inverter and charge controllers divided by average power delivery capacity of the system over the past 10 years.

Unfortunately even if I did not have a battery bank to maintain our electricity provider will only pay 2.4 cents/kW for grid tie energy(which I suspect is significantly lower than wholesale cost from another provincial/state level grid provider). They would rather burden the province's rate payers with several decades of hydro dam building debt than encourage micro grid producers that would literally cost them nothing in capital debt related to renewable grid expansion. I would be literally loosing money by selling to them at that rate based on just my amortized equipment repair/replacement cost of roughly 4.6 cents/kW. I might be able to get that number down if I would scale my PV array significantly up but honestly I would likely never see a return on my initial investment.

 

[cregox]

i will double-check, but even if selling electricity to the grid won't pay more than what we buy from it (here in portugal), your arguments are not very reasonable @apu.

still i want to thank you for the input.

you started to count the costs from the perspective of a house owner who already paid for a lot of costs, and who benefited from a lot of city given in your location.

if you go somewhere where electricity is expensive or if we want to design a more sustainable and cheaper city, the solar panel will necessarily be cheaper than any other current way to produce electricity.

and if your end consumer costs appear to be bigger at any point, consider you might be counting illusionary numbers. in practice, you're just investing in your pioneering photovoltaic energy generation, which have its risks, but it's necessarily a net cheap costs.

here's the only cheaper (energy) technology i'm aware of... i have seen only the focused mirror prototype working, not the battery or the heat generator (which could easily generate electricity cheaper than photovoltaic). granted, the mirror is the hardest part to build with current (society/civilization) technology... but the guys seem to want to build everything from scratch!

a jürgen kleinwächter website (i still haven't memorized by heart) https://h2nrgy.com/videos/

 

[apu]

i will double-check, but even if selling electricity to the grid won't pay more than what we buy from it (here in portugal), your arguments are not very reasonable @apu.

still i want to thank you for the input.

you started to count the costs from the perspective of a house owner who already paid for a lot of costs, and who benefited from a lot of city given in your location.

if you go somewhere where electricity is expensive or if we want to design a more sustainable and cheaper city, the solar panel will necessarily be cheaper than any other current way to produce electricity.

and if your end consumer costs appear to be bigger at any point, consider you might be counting illusionary numbers. in practice, you're just investing in your pioneering photovoltaic energy generation, which have its risks, but it's necessarily a net cheap costs.

here's the only cheaper (energy) technology i'm aware of... i have seen only the focused mirror prototype working, not the battery or the heat generator (which could easily generate electricity cheaper than photovoltaic). granted, the mirror is the hardest part to build with current (society/civilization) technology... but the guys seem to want to build everything from scratch!

a jürgen kleinwächter website (i still haven't memorized by heart) https://h2nrgy.com/videos/

I appreciate your comments and certainly want to be clear that I not oppositional to solar energy or its benefits(financial, environmental or otherwise intangible). Rather I find it frustrating to hear how "cheap" it is or its "free energy". Its not and one has to be remain critical of some of the disadvantages even if you are a proponent.

 

[Genevamech]

The financials of home solar PV are more or less entirely supported by the savings from not buying grid power. Obviously if your grid power is very cheap then the financial benefit of PV is impacted.

Battery systems are basically never worth it if your goal is to save money. I don't know your circumstances but it sounds like building an island system with battery backup was a choice rather than a necessity? There's no point in that unless you have frequent blackouts, in which case the primary goal is reliability not cost saving.

Anyway, I maintain that the operating cost of a PV system is "essentially zero" since amortized costs will be on the order of a few hundred dollars per year at most. Payback is well within the lifetime of modern panels and inverters these days, though still about a decade or so for most people.

 

[apu]

Anyway, I maintain that the operating cost of a PV system is "essentially zero" since amortized costs will be on the order of a few hundred dollars per year at most. Payback is well within the lifetime of modern panels and inverters these days, though still about a decade or so for most people.

I dunno about operating costs being "essentially zero". Generally speaking my 10+ years experience with my current system tells me solar panels even with expected degradation will last for a relative indefinite amount of time. Inverters, charge controllers, and supporting electronics will not. I run relatively reliable "high end" Outback equipment and for the past 10 years I have had to replace a failed fan in charge controller, one of two inverter mainboards and one failed control panel. In all of those instances those items brought down my system entirely for days to weeks waiting for parts that cost in around $1200 cumulatively. Fortunately parts were available and I am handy enough to do my own repairs as 3+ remote call outs would be probably at least another $1200. I suspect the next time an inverter board fails(and it will) I may need to replace the entire inverter at a cost of $2000-3000 as there just won't be suitable parts available.

But just for fun lets omit any battery costs, alternate energy costs when system is down, panel degradation or labor to repair and lets say my costs were exactly $1200 for 10 years. Lets say I sold every theoretical kWh to my utility at their "generous" 2.4 cents per kWh. Based on my 3kW array this would come 38,430 kWh over 10 years( average production is 1281 kWh/year per 1kW of solar panels with average insolation in my area). I would have earned a grand total of $922.32 putting me in a negative $277 balance. Again I would be literally paying my utility a hefty premium to take my power. If you factor in the true costs and the fact that they would happily sell me back my own power at over 12 cents kWh the reality is even uglier.

 

[Jim Matthews]

The strongest argument for installing PV arrays here in the US Northeast (with relatively expensive grid power at $.20/kwh) is avoiding connection costs in remote areas.

It is no accident that the utilities underpay home producers for power.

 

[Genevamech]

But just for fun lets omit any battery costs, alternate energy costs when system is down, panel degradation or labor to repair and lets say my costs were exactly $1200 for 10 years.

So less than the cost of a "standard" Netflix subscription... okay... $10/month is "essentially nothing."

I would have earned a grand total of $922.32 putting me in a negative $277 balance.

Missing from your math is the $3,546.11 you didn't pay the utility company because you generated that electricity for $1,200 in maintenance costs instead of buying it for $4,746.11 (38,430 kWh at 12.35 cents/kWh). Your payback calculations are completely jacked because you're only looking at what the utility would pay you, rather than what you're not paying them. At least, that's how the finances work for typical grid-tie systems... does your utility not offer net metering or something?

 

[cregox]

so i double checked some information...

the panel we got installed here in portugal, and that i see installed all over the country when i drive around, got a 10 years subsided plan to get installed, in which you get paid more than what you but electricity for...

so, if we buy it for roughly 0.18 EUR, then we sell the generated energy for at least €0.2 during the first 10 years. after which it will be reduced to something ridiculous, probably less than 5 cents as it happens elsewhere.

what i meant is that even without this subsidiaries, it's still cheaper than any alternative in the net sum for the world.

and it still surely feels like free energy if you can keep the maintainance cost to zero. because it is essentially free, after installing it. living in the present.

a big expensive inverter is only needed if you need too much electricity. i highly recommend you to review your essential needs and how you get your energy. heating stuff can also be done very cheap without electricity, using other kinds of solar panel, and even wood.

if you live in the city, you're screwed. start by moving out. yes, there's enough land for everyone. no, not every land is owned by capitalists.

i think i've tried to pack too much in this message already.

sorry, i probably won't be able to follow up the expected unpacking questions... as i grew tired of this thread.

the whole "conflict" here became too pedantic.

please, refer to the internet. perhaps my humble (and terribly lacking) website can help.

cheers!

 

[OzKona]

Crikey, cregox, you give up quickly. Only one page and 13 messages and you're tired of the thread?

Can you give us a link to your website, please.

Happy New Year!

 

[cregox]

Crikey, cregox, you give up quickly. Only one page and 13 messages and you're tired of the thread?

Can you give us a link to your website, please.

Happy New Year!

it was already on my profile... but i really meant this ahoxus.org

yes, i love to move fast sometimes!

 

[apu]

So less than the cost of a "standard" Netflix subscription... okay... $10/month is "essentially nothing."



Missing from your math is the $3,546.11 you didn't pay the utility company because you generated that electricity for $1,200 in maintenance costs instead of buying it for $4,746.11 (38,430 kWh at 12.35 cents/kWh). Your payback calculations are completely jacked because you're only looking at what the utility would pay you, rather than what you're not paying them. At least, that's how the finances work for typical grid-tie systems... does your utility not offer net metering or something?

Missing from your math it the upfront capital cost of the solar system. Lets say I saved $3546.11 over the 10 years of solar production and then I divided the upfront cost of the system including install labor and minus a battery bank = $18,000. Wow that would only take 50 years for my energy to be "free" at which point I am pretty certain I will be long decomposed and if the array has survived the elements its degradation would probably be 50% or more(effectively done so you can add that to the amortized cost). I appreciate that energy rates are not static and they vary greatly depending in what part of the world you are in, that may affect the math once again but this is the best I can do with variables I am presented with. Again my point is not that I am against solar energy rather depending on your individual circumstances and competing utility rates it may not be as "cheap" as folks generally proclaim and its certainly not free. There is always a cost. Its more apparent if you remove the subsidies.

My utility is a crown corporation(government) utility monopoly that does not want any competition and is happy to dissuade folks from producing electricity on a cost effective basis. I mostly do it because I like the independence of being my own utility and I was able to minimize my cost with my own install and maintenance labor. At a best case scenario in context to my current utility rates If I ignore my upfront cost I am cost neutral with amortized battery replacement/ equipment repair cost to my current utility rates. For my circumstance selling my electricity to my grid provider and buying it back from them would be worse. Now assuming energy will cost more in the future the numbers may slightly edge in my favor at some point.

 

[apu]

so i double checked some information...

the panel we got installed here in portugal, and that i see installed all over the country when i drive around, got a 10 years subsided plan to get installed, in which you get paid more than what you but electricity for...

so, if we buy it for roughly 0.18 EUR, then we sell the generated energy for at least €0.2 during the first 10 years. after which it will be reduced to something ridiculous, probably less than 5 cents as it happens elsewhere.

what i meant is that even without this subsidiaries, it's still cheaper than any alternative in the net sum for the world.

and it still surely feels like free energy if you can keep the maintainance cost to zero. because it is essentially free, after installing it. living in the present.

a big expensive inverter is only needed if you need too much electricity. i highly recommend you to review your essential needs and how you get your energy. heating stuff can also be done very cheap without electricity, using other kinds of solar panel, and even wood.

if you live in the city, you're screwed. start by moving out. yes, there's enough land for everyone. no, not every land is owned by capitalists.

i think i've tried to pack too much in this message already.

sorry, i probably won't be able to follow up the expected unpacking questions... as i grew tired of this thread.

the whole "conflict" here became too pedantic.

please, refer to the internet. perhaps my humble (and terribly lacking) website can help.

cheers!

I assume this comment is directed at me as I feel I am the only one disagreeing with your assertion that solar energy is "essentially free" based on your individual cost of supplied grid energy and available subsidies to produce your own. I am truly happy and envious of your circumstances but that is not my reality nor do I feel its universal.

As far as your comments regarding reviewing essential needs and not getting more equipment than you need is great advice. I guess i have to provide some details so you can appreciate that I have indeed made those considerations well before I designed and built my system some 10 years ago.

We have a relatively small 245 Acre( roughly 100 Hectare) cattle farm. The original plan was to provide enough electricity in our 1100 sq/ft farm house for general, lighting, refrigeration, small appliances, TV shallow well for watering ourselves, livestock and a 9000 btu mini split AC in the summer months. Heating is done with a wood stove and propane for back up forced air furnace and stove. The 3kW solar array( ten 300 watt polycrystalline panels statically mounted at 45 degrees due south. This maximized average seasonal insolation and minimized snow covering) feeds a 20kW(10 kW usable) 48V lead acid battery bank(sixteen 6V GC batteries wired in series in 2 parallel strings, wiring oversized and otherwise designed/maximized for DC efficiency) via a single Outback 80 amp mppt charge controller. The 48V DC storage is then inverted to a single phase 120V AC via a 3.6kW Outback sine inverter. This effectively provides the house a 30 amp supply for the items I mentioned(keeping in mind most modern residential buildings have 100-200 amp 240 dual phase supplies). For most months this supply is sufficient for my needs. December and January often need augmentation with a 2kW Yamaha inverter gas generator because there is insufficient seasonal insolation. At some point I would like to add another array (positioned to east and west directions)and charge controller to minimize the reliance on the generator in winter months. I will probably wait until this current inverter is on its last legs and then upgrade to 60 amp 240V dual phase 48V inverter setup. That would allow me more options to supply outbuildings, level 2 EV charging and perhaps move to a deep well pump instead of my current shallow well arrangement. To that extent I have even entertained engineering a mini grid system with interconnected multiple arrays, inverters but that's probably overthinking it for the moment

I am sorry you feel this discourse has become a pedantic conflict for you. That certainly has not been my intention.

 

[Genevamech]

Missing from your math it the upfront capital cost of the solar system

It's the same in both scenarios. Also yes, solar PV doesn't necessarily work financially for all people in all locations, or for all systems. However, the average payback for solar PV - in Canada - is about 10 years. I've seen claims ranging from 8 to 16 years, but the average is 10.

Also also, the electric utility here is also a government regulated monopoly and they just about bend over backwards to encourage homeowners to install PV, so the "government" part seems less relevant than the fact your utility does net billing rather than net metering for whatever reason.

Lastly, I just want to point out that the comment in dispute here has morphed from "the operating costs is essentially zero" to "it's essentially free" which is so far removed from the original connotation it's bordering on offensive.

 

[electriceddy]

Photovoltaic, i.e. "solar panels" - the kind that produce electricity. There is also solar thermal panels which use sunlight to heat up water (or sometimes oil) so sometimes just saying "solar power" isn't specific enough.

Somewhat similar describing to my combination solar/ wind clothes dryer setup...

I still however have to find a way to charge my EV with this equipment